Hair 101

Everything You Wanted to Know About Your Tresses

Love, hate, envy and betrayal. They define our messiest relationships—including the one we have with our locks.

That’s why we’ve sought the scoop on scalps from The University of Texas Health Science Center at Houston (UTHealth) expert Adelaide A. Hebert, MD, a dermatology and pediatrics professor at UTHealth Medical School.

First, know your enemy. Hair is more than a four-letter word and title of a ‘60s musical. The threads of keratin on our heads sprout from sacs or follicles, derived from the Latin follies, or bags. Strands elsewhere stop growth only to a certain point. Those atop our scalps extend six inches yearly, with 90 percent of follicles laboring at a time. The fibers have no feelings, even when you chop or berate them, but follicles do. (Thus, pulling hairs stings briefly.)

Yet you can manipulate your mane, notes Hebert. Dye transforms silver highlights into other shades, heat can straighten or curl, while silicone and other products can thicken strands and even smooth cuticles on the shaft, making hair seem glossier and healthier.

Four More Head Scratchers

ITCHY SCALP: If your scalp itches, you may have psoriasis (a skin condition that leaves red, scaly patches), seborrhea dermatitis (aka dandruff) or lice. “Kids catch lice at school,” Hebert says. “Check the scalp at the nape of the neck or the center of the collar and look for nits, which look like small white or yellow-brown specks on the hair shaft.”

Medicated shampoos treat all three conditions, but get your dermatologist’s suggestions on which to buy, she says. Rotate them to avoid your scalp adapting to a product, leading to poorer results. Leave treatments on for 10 minutes.

STRAWLIKE STRANDS: Hormonal changes, excessive chemical use (color, perms or straightening within two weeks of one another) or use of antihistamines and antidepressants can strip strands of oil and slow scalp circulation, leading to dry strands. RX: Shampoo less frequently, avoid products containing hair-drying alcohol, methanol and ethanol and reduce use of hair-frying dryer/flat irons—and chemical treatments.

OFF-COLOR COIFFURES: Pool chlorine can turn blonde hair green, while sun and salt water can dry it. RX: Rinse right after swimming (or wear a swim cap) and use UV-protectors and hats. Hair becomes more porous with age, making it more likely to suck up chemicals in tap water.

TOXIC HAIR STRAIGHTENERS: Fortunately the US Food and Drug Administration nixed the use of extreme straighteners, so they no longer are widely available. “The new Brazilian hair straighteners are not as harsh—and the hair looks good,” Hebert says. “Go to a hairdresser you can trust.” Be aware: Less dangerous versions are less odiferous. But you won’t be able to put your hair behind your ears or wear glasses for three to five days with some of these Brazilian treatments for hair straightening.

4. Your thyroid. An overactive or underactive thyroid can cause you to shed.

5. Traumatic events. Giving birth, breaking up, having surgery or suffering a bad bout of flu can lead to molting as follicles shift into their resting phase, known as telogen. Once aggravation ceases, growth restarts. “But since hair only grows a few millimeters a month, it can take four months to a year to see a difference,” Hebert says.

6. Drugs. Even ibuprofen (Advil, Motrin) and other non-steroidal anti-inflammatories can chase hair away. So may anti-seizure drugs and some blood-pressure medications. Sometimes starting—or stopping—birth control pills may cause hair loss. “If you see a dermatologist about your hair, you should bring recent blood tests and a list of all prescribed drugs, even over-the-counter meds, food supplements and vitamins you take. All may affect you hair,” Hebert says.

7. Your immune system. If it kicks into overdrive, you may get alopecia areata (round patches of hair loss) or, worse, alopecia totalis—complete baldness—which happened to Princess Caroline of Monaco. “Sometimes the condition resolves itself, but do not put off seeing a doctor. Your immune system is allergic to something in the hair bulb, and the longer you wait, the harder it is to treat,” Hebert says.

8. Ringworm. This should be treated quickly before irreversible scarring occurs, Hebert says. “We hate for a child—or adult—to go without hair all their life from something that’s highly treatable.”

9. Syphilis. This sexually-transmitted disease causes tiny circles of baldness as if moths attacked your scalp, but can be treated with penicillin.

If you’re at a loss about your loss, “seek the true experts—dermatologists,” Hebert says. “We’re the ones with the most comprehensive training in hair loss. We can assess causes and treat them.”

Not only will your medicines and lifestyle be reviewed, but your doctor may prescribe minoxidil (Rogaine) or other drugs to promote hair growth, while monitoring for dangerous side effects, such as lowered blood pressure, sudden weight gain, rapid heart rate, chest pain and swollen feet. Minoxidil’s benefits cease if you stop the medicine.

“But there’s no miracle grow,” Hebert says. “Do not expect the dermatologist to wave a magic wand for instant results. It takes four to six months to start that process.”

Mane myths

Think you know everything about hair? Take our “Tress True-or-False Test” to see how knowledgeable you are:

Pluck (or shave) a hair (gray, brow or chin) and even more will grow back. False. “It’s just not true,” Hebert says.

Hair grows faster in the summer—or if you trim it. False, at least visibly. “If at all, the difference is only millimeters,” Hebert says. “The one exception would be in patients with psoriasis and alopecia, as those autoimmune conditions improve in summer.”

The more expensive the shampoo, the better. False. Dermatologists recommend—and often use—drugstore brands. “High-end products are not necessary,” Hebert says. But super-sensitive scalps need hypoallergenic shampoos that are gentler than baby shampoos.

This site is intended to provide general information only and is not intended to substitute for or be used as medical advice regarding any individual or treatment for any specific disease or condition. If you have questions regarding your or anyone else’s health, medical care, or the diagnosis or treatment of a specific disease or condition, please consult with your personal health care provider.

About Dr.
Adelaide
Hebert

Dr. Adelaide Hebert is a professor and director of Pediatric Dermatology at UTHealth Medical School.